


The Actual Medical Implications of Hanahaki Disease, a semi-scientific rant by me

by novaauster



Series: Nova's Hanahaki Theories [1]
Category: Original Work
Genre: Hanahaki Disease, Science Fiction
Language: English
Status: Completed
Published: 2021-02-06
Updated: 2021-02-06
Packaged: 2021-03-18 17:49:17
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,763
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29247564
Author URL: https://archiveofourown.org/users/novaauster/pseuds/novaauster
Summary: Welcome to a long and insightful rant about something that’s really not that deep! If you use this information/theory for a fic I'd love it if you tagged or credited me in it!(warning: this is about a fictional lung disease and talks about medical practices and death. it's not graphic but it is in detail, like there's no description of hanahaki happening to a character but it's a semi-scientific paper about it so symptoms and treatments are named)
Series: Nova's Hanahaki Theories [1]
Series URL: https://archiveofourown.org/series/2166870
Comments: 4
Kudos: 20





	The Actual Medical Implications of Hanahaki Disease, a semi-scientific rant by me

So I have been recently introduced to the fanfic trope of hanahaki disease. It’s a great trope, love the hurt-comfort, angst, and mortal peril, don’t love the unhappy endings, but that’s a matter of opinion. The biggest flaw of this trope is its medical implausibility! Like all one-dimensional villains, it seems like its only purpose is to hurt the main character, but diseases just don’t work like that.

From my extensive research (google searches and a reading total of two (2) fics), I have concluded that this disease has many variations (mutations?), but there are universal symptoms. These include the fact that is a respiratory disease that takes root in the lungs of a person who has fallen in unrequited love and grows objects that appear to be flowers somewhere in the lungs. The “flowers”, for unexplained reasons, fall off of the stem and can be coughed out. Patients with foreign bodies in the lungs for long periods tend to become asymptomatic, so the continuous coughing that is the hallmark of this disease implies that the “flowers” are continuously moving, growing at a rate much faster than most plants can, or are moved with the breathing of the patient, but since the patient cannot expel them all on their own, the latter implication that the disease is weak can be ruled out. 

The disease can end three ways: deadly suffocation, sudden expelling of the “flowers” caused by a confession of love by the patient’s crush, which rarely or never causes pneumonia afterward despite extensive damage to the lungs, or a surgical thoracotomy (cutting open the bronchi) that results in the loss of all the patient’s memory of their crush. This last possibility is the most fascinating one because it means that the disease has roots in the brain, specifically the hippocampus, which is involved in episodic and recognition memory. 

So we have three questions to have answered: What type of disease is it, why does it take root in human lungs, and how can a thoracotomy remove memories?

The first question is probably the easiest. First of all, the disease is clearly parasitic, as it grows inside a living thing to its detriment and, though technically a virus might be able to rewrite your DNA to force your tissue to grow in the form of flowers and a bacteria might grow to resemble them, there’s no reason for either of them to. It’s discernibly not an animal, and though it does appear at first glance to be a plant, it is not. That is because plants are autotrophs: they create their own food. Hanahaki disease feeds on the patient, and it grows quickly but is not harmed at all by pruning itself: expelling its “flowers” directly, precisely, up into the trachea, where they can be coughed out. You cannot cough out something deep inside of your lungs, so the disease must benefit from the coughing to allow the “flowers” to reach the trachea. 

A parasitic plant that needs some specific nutrient from a body, that appears out of near-nowhere, that prefers to live in a dark, damp place and uses human blood to water itself but doesn’t seem to need a vascular system, and grows and expels fascinatingly-shaped pieces of itself overnight? That’s a fungus! 

Hanahaki flowers are actually mushrooms in disguise! This makes perfect sense if it evolves along with modern medicine, as a doctor might not think of fighting it with antifungals if it presents as a plant. Clever little parasite!

Fun fact: Since victims of hanahaki disease die of suffocation, not poisoning, though the fungus roots itself into their blood vessels, this implies that it is not poisonous or venomous, so you could absolutely clean the “flowers” off, fry them up, and serve them as gourmet. That’d spice up Twilight’s mushroom ravioli scene (/j), but actually, it would be a cool-as-hell horror story if a main character deliberately got hanahaki (or was forcefully given it, though I don’t know how that might work) in order to sell the flowers to some fancy (probably French) chef who believed they contained the secret to love or something. It would be a great commentary on capitalism, bodily autonomy, blind belief in urban myth, death, and love. If anyone writes or has written this, let me know. 

The second question we need to answer is why it takes root in human lungs. 

Fungi are known to reside in the lungs because they are dark, damp, and full of nutrients. The fungus Aspergillus is the most common pulmonary fungus, so we will use it as a base. Patients with Aspergillus can be asymptomatic, or they can have a fever, bloody cough, difficulty breathing, and chest pain. Aspergillus spores exist everywhere, and we can often inhale them without getting infected, but it is opportunistic, so it can take advantage of those with weakened immune systems and infect them. It can become invasive, affecting the kidneys or liver, and if it does so, it is almost always fatal.

Hanahaki isn’t shown to have an asymptomatic stage, but that doesn’t mean it doesn’t have one. It doesn’t always cause a fever but does cause a bloody cough, difficulty breathing, and, in the late stage, chest pain. It is unclear where hanahaki spores originate from, but as the patients can fall in love and come down with hanahaki anywhere (in mysterious ways, according to Ed Sheeran), it must be assumed that they are invasive, can exist anywhere, and can affect patients opportunistically.

Hanahaki differs from Aspergillus in two ways. One: patients cough up the mushrooms, which is likely an efficient way to spread spores, and two: it becomes symptomatic in those with unrequited love, not weakened immune systems. In fact, according to the paper “Falling in love is associated with immune system gene regulation” by researchers from Tulane and the University of California, falling in love makes the immune system stronger. It doesn’t specify whether unrequited pining also makes it stronger, but my paper is only semi-scientific, so I’m just going to ignore that. Though loneliness and depression are proven to have physical effects on the body, my point is that hanahaki cannot be fought off by the body’s natural defenses, and it takes advantage of something other than physical weakness.

Hanahaki canonically takes advantage of love. The chemicals and hormones associated with love include dopamine, norepinephrine, and adrenaline. Oxytocin and vasopressin are associated with requited, long-term love. Dopamine, norepinephrine, and adrenaline are all associated with energy and heightened blood pressure, and often with fear. Oxytocin and vasopressin lower blood pressure and cause feelings of calm. 

This implies that hanahaki feeds on blood, and does it quickly, spreading its mycelium and hyphae all around the cardiovascular system, and needs nutrients associated with not love, but fear, and energy. The stress hormone, cortisol, is a steroid, so it could increase hanahaki growth. Hanahaki definitely needs energy to grow as quickly as it does and compensate for the constant loss of its mushrooms and spores. Once the patient’s crush confesses, the patient calms down, because they are glad that they now have a lover, and they are glad that the hanahaki will no longer kill them. 

However, herein lies several rubs. Dopamine, norepinephrine, and adrenaline do not disappear after the confession and continue lowering for years until they level out. And oxytocin can be released by things other than a confession of love, so it’s evolutionarily unlikely that it is deathly toxic to hanahaki, especially if all the efforts of the immune system don’t put a dent in it. 

So here’s my theory: Hanahaki feeds on the patient’s mounting fear to spread through their body and take permanent root in their cardiovascular system. The symptomatic disease is only its reproductive stage: it lives in the lungs to spread its pores, and then hides, lulling everyone into a mostly-false sense of security by making it look like it has died after the confession, so the patient has no qualms about breaking any quarantine they might have had. After the confession, all of the spores are expelled, and if there is a true-love’s kiss the spores are spread into the lover’s lungs, so after the statistically-likely breakup the patient’s lover’s new crush can cause the lover to develop symptomatic hanahaki, while it lies dormant in both of the lovers during their established relationship.

Humans are the only animals that kiss. Hanahaki takes advantage of that to spread, and, as such, only takes root in human lungs.

The final question is the trickiest. 

The most common, though still very uncommon, fungal disease of the brain is fungal meningitis. It has many symptoms inconsistent with hanahaki, however, including a stiff neck, high fever, sensitivity to light, nausea, seizures, hearing, balance, and vision loss, kidney failure, and many more! Essentially, meningitis is infected cerebrospinal fluid, which inflames stuff in the brain and just goes berserk, messing up anything and everything without much planning. Hanahaki only targets the hippocampus’ memories, causing problems on purpose. 

Now, this has potential. Hanahaki, traveling from the lungs into the cardiovascular system and into the brain, needs some very important reason to target the memories. Of course, it could just be an incentive for the patient not to do surgery, but the precision with which hanahaki acts implies something far more evolved. I think hanahaki targets the hippocampus so it can make the brain replay memories that release the hormones it feeds on. It deliberately increases panic and obsession in the patient and decreases their rational decision-making so it can keep releasing spores until the very last minute. That’s the best explanation for why patients in hanahaki fics never suck it up and confess to their lover, even under mortal peril: the hanahaki is precisely driving them insane with memories of fear and stress. Again, if anyone wants to write a horror instead of a star-crossed romance with this concept, tell me.

In conclusion, hanahaki disease is a terrifyingly advanced fungus that feeds on blood and hormones, takes advantage of love and fear, the best and worst of human nature, to reproduce, and can lie dormant as a commensal in the cardiovascular system for years before and after it becomes a violently active parasite in the pulmonary system and brain. It manipulates memories and creates vicious cycles of panic. It tricks patients, lovers, and doctors with its disguised mushrooms and spores and its dormant stage, and is unresponsive to modern medicine or the immune system. It outsmarts us. If hanahaki were real, you’d best pick a god and pray to be aroace.

**Author's Note:**

> I also posted this on Tumblr @novaauster. If this goes viral I'm going to send it to either my biology or my English teacher, or possibly both if it goes really viral (or fungal, lmao).


End file.
